Means of controlling the angle of incidence of aero revolving blades or wings and propellers



March 18, 1930. Y 1,750,778

; D. MEANS OF VCONTROLL N THE G OF INCIDENCE OF AERO REVOLVING 13 ES OR WI AND PROPELLE Filed Dec. 15, 1927 heats-Sheet 1 D. KAY

March 18, 1930. 1,750,778

7 MEANS OF CONTROLLING THE ANGLE OF INCIDENCE OF AERO REVOLVING BLADES OR WINGS AND PROPELLERS 2 Shets-Sheet 2 Filed Dec. 15, 1927 Patented Mar. 18, 1930 V UNITED. STATES PATENT OFFICE Y DAVID KAY, OF BLACKF ORD, SCOTLAND.

MEANS OF CONTROLLING THE ANGLE 0F INCIDENCE OF AERO REVOLV ING BLADES OB wmes AND PRorELLnns Application filed December 15, 1827, Serial No.

This invention relates to variable pitch air screws, aero-revolving win s or propellers. The object of the invention is toprovide simple and efficacious means whereby the an-' gles of incidence of the blades of airscrews, aero-revolving wings or propellers may be varied to suit flying or propellingconditions manually, or mechanically or automatically. To the attainment of the above mentioned object, according to the present invention, blades of airscrews, aero-revolving wings or propellers are provided with means for carrymg arranged that the effect of the rotation of said means in one direction, or of a force oposing the rotation of the blade is to cause the lade to move backward in a reverse direction to the direction of rotation of the airscrew, aero-revolving wing or propeller and also to turn about its longitudmal axis so that its angle of incidence is varied. The said means comprise a member or members whereon the blade is mounted, whose axis or common axis is arranged at an angle to the common axis of bearings in which said means is turnably mounted, and in cases where it is permissible to use blades having split. bosses, said means may consist of a solid (as opposed to builtup) form of blade-carrying member (which I prefer. to call a hinge-pin member) comprising two co-axial parts turnably arranged .in hinge-pin supporting means carried by the propeller or like shaft, and .a crank pin member on which the blade of the airscrew, aero-revolving wing or propeller is turnably arranged and whose axissis inclined to thecommon axis of said co-axial'parts. Constructional forms of built-up hinge-pins are described hereinafter.

Manually, mechanically or automatically operated means may be provided for operating said hinge-pins in order to vary the angles of incidence of the blades. One form of automatically operated means applied to an airscrew depends for its operation on the resistance actmg on the blades and opposing the rotation of the airscrew. These means include mechanism which comprises resilient means opposing the rotation of the hinge-pin members, the said resilient means consisting said blades which are so constructed and 240,288, and in Great Britain'l'anua'ry 4, 1927. v

rovided'on an axially movcific forms of hinge-pins and one arrangement for the automatic variation in'fiight of the pitch of the airscrew blades of an aeroplane.

Fig. 1 is a view of' one form of hinge-pin adapted for use when the boss of the blade of anairscrew or rotating wing is made up of two connected-together parts;

Fig. 2 shows a built-u form of hinge-pin Fig. 3 also shows a bullt-up form of hingepin particularl adapted to be used for rotating wings o the auto-gyro type;

Fig. 4 is a front view of an airscrew in which the angles of incidence ofthe two blades are variable automatically in flight;

Fig. 5 is a fragmentary side view of said so airscrew;

Fig. 6 isa fragmentary front view, to a larger scale," illustrating the mounting and arrangement of the hinge-pins and their connecting mechanism and Fig. 7 is a fragmentary slde view, also to a larger scale, corresponding to Fig. 6.

Referring to the drawings :V The hingein shown in Fig. 1 consists of two co-axial anges 1 and 2 which are interconnected by a crank pin 3. The latter is inclined to the common axis of the flanges, the mid-point of the axis of the pin coinciding with the mid-point of the common axis. The said flanges are extended, respectively by coj ournalled in bearings formed in means (not shown) for carrying the bin e-pin. This axial coned extensions 4 and 5, which are type of hinge-pin is adapted to e used when it is permissible to construct the boss 6 of the blade in two detachable parts. The said boss could, however, be made solid by making the J clined to the'axis of the member. As will be seen, the flan e 10 bears on one face of the boss 6 of the lade of the airscrew, and, in

' i order to prevent lateral movement of said boss, a loose flange 12 is slipped over the pin 7, the bore 13 of said flange being co-axial with the bore 11. The flange 12 is correctly located relatively to the pin 7 by means of a dowel peg 14 fitting into a hole formed in the end of said sleeve member. Movement of the flange 12 axially along the pin 7 is prevented by means of a sleeve 15 mounted on the pin 7 and retained against the flange 12 by means a of a nut '16 which is screwed on to the screw: threaded end of the pin. The sleeve 15 is journalled in a bearing formed in the hingepin supporting means (not shown).

The form of hinge-pin shown in Fig. 3 is particularly, although not essentially, adapt- 8 ed for use with rotating wings, such, for ex-.

. ample, as are used on the auto-gyro form of aircraft. The hinge-pin comprises a plain cylindrical in 17 which is keyed to the inner races 18 an 19 of two roller bearings. The outer races 20 and 21'of the said bearings are secured, respectively, in recesses 22 and 23 formed in the opposlte faces of the boss 6- of the rotating wing, rollers 24 being interposed between -the inner and outer races. The pin 17 "is keyed in co-axial bores 25 and 26 formed, respectively, in the inner races 18 and 19, the common axis of the bores '25 and 26 being inclined to the common axis of the outer races and, consequently, to that of the .recesses 22 and 23. The parts of the pin 17 projecting beyond the inner races of the roller bearin s are adapted to be journalled in bearings ormed in hinge-pin su aporting means (not shown). Ball or plain earings be used instead of the roller bearings. order to vary the angle of incidence of the blade of the airscrew or rotating wing it is only necessary if the change in the 'angleis to be carried out by manual or mechanical means, to turn the complete hinge-pin in Fi s. 1 and 2, and the pin 17 and. races 18 and 19 of the hinge-pin in Fig. 3. On the other hand, a resistance opposing the rotation of the blade will, if the hinge-pins of Figs; 1 and 2and the pin .17 and races 18 and 19 of the hinge-pin in Fig. 3 be set in a favourable position in which the hinge-pins 'faces with a facing 52 or pin 17 are not in a dead-point position,

cause the rotation of said hinge-pins or the pin, the blade being thereby turned about its longitudinal axis and its angle of incidence altered.

The manner in which the hinge pins may of the blades 6 and 6 of an airscrew are varied automatically, without intervention,

on the part of the ilot, by making use of the resistance on the lades opposing the rotation of the airscrew. The blades 6 and 6" are each associated with a hinge-pin of the kind described with reference to Fig. 2, but in the case of rotating wings for aircraft of the auto-gyro type, the form of hinge-pin shown in Fig. 3 could advantageously be used. The journals 8 and 8 and the sleeves 15 and 15 of the pins 7 and 7 are journalled, respectively, 1n bearings 27 and 27 a and 28 and 28" formed in forwardly projecting flanges 29 and 30 provided on a flange member 31, which is adapted to be secured to a corresponding flange on the propeller shaft of the aircraft. Levers 32 and 33 are secured, respectively, on the pins 7 and 7 and are 'connected to a lever 34 by means of links 35 and 36, each of which is adjustable in length and in swivelling connection with the lever 32 or 33, as the case may be, and thelever 34; The lever-34 is formed with a central boss 37, which is slidably and turnably arranged on a shaft 38 provided on a transverse plate 39 fixed to the two flanges 29 and 30. The outer end of the said boss is formed with a number of inclined teeth 40, which are adapted to engage in correspondingly shaped notches 41 formed in a member the shaft 38 but prevented from turning thereon by means of feathers 43 provided on the shaft. The teeth 40'and notches 41 are normally held in enga ement by means of :1. C011 spring 44 arrange between the member 42 and a collar 45, whose position on the shaft 38 1s adjustable by means of lock nuts 46 and 47 screwed on to the threaded end of the said shaft. A thrustbearing 48 is interposed between the lever 34 and the plate 39.

In order to take up any fore and aft thrust of the. ad'acent ends of the blades 6 and 6, each of t e latter is provided with a shoe 49 carried by a pin 50 secured to a member 51, which is connected to the boss of the blade. The said shoes bear lightly upon each other during the relative movement of the two blades, their outer faces contacting with the inner face of the plate 39 and their inner rovided on the leadin face of the flan e 3?. I

he strength oft e spring 44 is arranged,

42 slidably arranged on- Y or is adjusted by the nuts 46 and 47, so that when the air-screw is stationary, the angles of incidence of the blades 6 and 6 are at a maximum, while, further, the hinge-pins are set so that the sleeves 9 are not in dead point positions, from which the hinge-pins could not be moved by pressure applied to the leading edges of the blades. The angles of incidence of the blades remain at a maximum until the blades are subjected to a resistance R, opposing their rotation and acting on their leading edges, which is sufficiently strong to cause them to move backward against the action of the spring 44 and in a contrary direction to the direction of rotation. The tendency of the blades to move backward has 'the effect, see Fig. 6 of tending to cause the The resistance opposing the rotation of the blades is communicated to the levers 32 and 33, which tend to turn towards each other but will be unable to do so until the resistance to the rotation of the blades is sufliciently high to permit the spring 44 to be compressed. When such a condition is reached,

the lever 34 is turned about its axis,and the inclined teeth 40 on theboss 37 of said lever bear against the walls of the correspondingly shaped notches 41, in the member-42 (which is held against rotation) and thus move said member to the right as viewed in Fig. 7, thereby compressing the spring 44. As soon as the resistance is wholly or partly taken off the blades 6 and 6 the spring 44 forces the member 42 to the left and the lever 34 and blades Sand 6 are turned in the reverse directions.

The strength of the spring 44 will be such that it will commence to be compressed as soon as the load on the engine passes a certain predetermined maximum. The resistance on the blades 6 and 6 will vary according to the conditions and to the height under and at.

which the aircraft is flying.

It will be understood that I do not restrict my invention to use on aircraft. The invention is equally applicable to marine, reversible pro ellers. Further, when applied to aircraft, the invention may either be applled to the blades of an airscrew as specifically described above, to the revolving wings of helicopters, or the revolving wings of aircraft of the auto-gyro type. may also arrange to vary the angles of incidence of the blades by manual or mechanical means operable or controllable, at will, from the pilots cockpit of an aircraft or from any suitable position in a I ship when the invention is applied to the propeller .or propellers thereof. Such modifications will be quite obvious to those sk lled in the art and need not be descrlbed specifically.

I claim 1. Means to mount a propeller blade on its shaft so that its angle of incidence can be varied, comprising a hinge-pin journaled transverselyon the end of the shaft, bearing means for the boss of the blade carried by said pin, the bearing surfaces of said means being so inclined that theaxis of the boss mounted thereon lies at an angle to the axis of said pin, and means to control the rotation of said pin;

2. Means to mount a propeller blade on its shaft so that its angle of incidence can be varied, comprising a hinge-pin journaled transversely on the endof the shaft, the central portion of said pin having a cylindrical portion to receive the boss of the blade, the axis of said cylindrical portion standing at an angle to the axis of said pin, and means to.

control the rotation of said pin.

3. Means to mount a propeller blade on its shaft so that its angle of incidence can be varied, comprising a hinge-pin journaled transversely on the end of the shaft, the central portion of said pin having a cylindrical portion to receive the boss of the lade, the

axes of said portion and of said pin being rel atively inclined, flanges at the ends of said portion with their inner faces at right angles to the cylindrical surface thereof, and means to control the rotation of said pin.

, 4. The combination of a propeller shaft having a disk-shaped end, a pair of spaced parallel lugs on the face of said end, a pair of hinge-pins journaled in said lugs, each of said pins being provided with a central cylindrical part the axis of which is inclined to the axis of the pin, and means to control the rotation of said pins.

5. The combination of a propeller shaft having a disk-shaped end, a pair of spaced parallel lugs on the face of said end, a pair of hinge-pins journaled in said lugs, each of said pins being provided with a central cylindrical part the axis of which is inclined to the axis of the pin, flanges at the ends of said part with their inner faces at right angles to the cylindrical surface of said part, and means to control the rotation of said pins.

6. The combination of a propeller shaft having a disk-shaped end, a pair of spaced parallel lugs on the face of said end, a pair of.

hinge-pins journaled in said lugs, 'each of said pins being provided with a central cylindrical part the axis of which is inclined to the axis of the pin, an arm on one end of each pin, a plate secured to said lugs, a lever pivoted on said plate, a link swiveled to each end of said lever and to the end. of the adjacent arm and yielding means to resist the swinging of said lever. 1

7. In a propeller structure forairplanes and the like, means for mounting the blades on the shaft so that their angles of incidence can vary with the a ir resistence' to their revolution, said means comprising hinge-pins 'journaled transversely on the enlarged end of the shaft and yielding means connected to said pins to resist their rotatioxnthe central cylindrical surface of each pin being inclined toiits axis and the blades being mounted on said surfaces.

In witness wherecf I have signed this specification.

VDAVID KAY. 

